As a method of inspecting or observing a biological sample extracted from a human body, an experimental animal, or the like, a method of manufacturing a thin slice from an embedding block is known in which a biological sample is embedded by an embedding agent, performing a staining process with respect to the thin slice, and observing the biological sample.
In recent years, a thin-slice manufacturing device capable of automatically performing an operation of manufacturing the thin slice has begun to be provided. Such a thin-slice manufacturing device manufactures a thin slice by relatively moving a cutting blade and an embedding block in a predetermined feed direction and cutting the embedding block with a thickness of several μm (for example, 3 μm to 5 μm).
Incidentally, when the above-mentioned thin slice is manufactured, the embedding block should be cut in a specific cross section such that a tissue (a biological sample) to be inspected or observed appears on a surface thereof. Conventionally, while the embedded tissue is embedded such that a cross section to be sliced and observed is parallel to an end surface of a block, the cross section is not completely parallel to the end surface. For this reason, in a slicing operation by a microtome, an operation called surface shaping is performed. The surface shaping is an operation in which an operator repeats the adjustment of the inclination of the embedding block and slicing the embedding block until the cross section of the tissue to be observed appears on a surface thereof when observing the embedded tissue. A thickness of the embedding block cut upon the surface shaping is relatively thick, and the cutting is referred to as rough cutting.
The embedding block processed by the above-mentioned thin-slice manufacturing device is constituted by two types of an embedding block upon termination of the above-mentioned surface shaping and an embedding block that is still uncut. The above-mentioned thin-slice manufacturing device requires surface matching when the embedding block upon termination of the surface shaping is processed. The surface matching is a work of measuring the inclination of the end surface of the embedding block to adjust the inclination such that the end surface becomes parallel to the cutting surface of the thin slice manufacturing apparatus.
As a technology of performing the surface matching of the cutting surface, for example, a technology disclosed in Patent Document 1 is known. In the technology disclosed in Patent Document 1, positions of three corners of the embedding block are detected using a sensor, and the surface matching of the cutting surface is performed based on the positions of three corners.
As a technology of automatically performing the surface shaping of the uncut block, there is a technology disclosed in Patent Document 2. In the technology disclosed in Patent Document 2, the block end surface is imaged for every cut, and the surface shaping is performed based on a variation in an area of the exposed tissue.